important milestone, almost three years since a wave of additional u.s. troops deployed to afghanistan in a surge designed to cripple the taliban, defeat al qaeda, and give afghan forces sat part they need. this morning, the last of those americans are out. it was december 1, 2009, at west point, that president obama announced the surge. >> and as commander in chief, i have determined it is in our vital national interest to send an additional 30,000 u.s. troops to afghanistan. >> reporter: at that time he also announced a schedule for their withdrawal, a goal that has now been met. 33,000 u.s. troops took part in the surge. 10,000 of them were out by july of last year. and the remaining 23,000 are now gone. but in his statement, the defense secretary had a sobering reminder, saying, "it is important to underscore that even as our surge troops return home, there are roughly 68,000 americans who remain in a tough fight in afghanistan, alongside their nato and afghan partners.